Re: [PATCH v4 00/25] multi-pack reachability bitmaps

From: Jeff King <peff@peff.net>
Date: Aug 25, 2021, 07:36 UTC
Message-ID: <YSXy73lWKteiuY6s@coredump.intra.peff.net>
In-Reply-To: <YSWmhMID1hGs7Yp1@nand.local>

On Tue, Aug 24, 2021 at 10:10:12PM -0400, Taylor Blau wrote:

Show 21 quoted lines

> > It's not clear to me that we have a resolution on whether calling "cd ..
> > && git multi-pack-index write --object-dir repo.git" is supposed to
> > work.
> 
> My recommendation would be to do the following things, all in a reroll
> of this series:
> 
>   - Fix the bug by which we would delete a .rev or .bitmap file out of a
>     different object store than we were working in (when the caller
>     passes `--object-dir`).
> 
>   - Disallow running `git multi-pack-index` outside of a Git repository.
> 
>   - Restrict `--object-dir` to only work with alternates of the
>     repository in the current working directory.
> 
> To me, that seems like both the least-surprising behavior, and what
> would lend itself to the easiest implementation. I would probably argue
> that the existing behavior (where `--object-dir` would work against
> arbitrary repositories) is a bug, and shouldn't continue to be
> supported.

All of those seem reasonable to me, and are what I would suggest if we were starting from scratch. My only hesitation is whether people are using the weird behavior of --object-dir in the wild (e.g., are bup folks relying on it).

Johannes, is this something you're using _now_, and it works, or something you hoped to use in the future?

In a sense, "hope to use" does not make you any less disappointed. ;) But what I'm wondering is whether using --object-dir from outside a repo entirely is actually something that even works. I.e., would we be disabling a behavior that was not intended, but does happen to work? Or are we closing off a possibly buggy and half-working part of the system?

-Peff